U.S. patent number 10,326,546 [Application Number 14/624,723] was granted by the patent office on 2019-06-18 for directional synchronization signals in wireless communications.
This patent grant is currently assigned to QUALCOMM Incorporated. The grantee listed for this patent is QUALCOMM Incorporated. Invention is credited to Omar El Ayach, Junyi Li, Ashwin Sampath, Sundar Subramanian.
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United States Patent |
10,326,546 |
El Ayach , et al. |
June 18, 2019 |
Directional synchronization signals in wireless communications
Abstract
Methods, systems, and devices are described for directional
synchronization signal signals in a millimeter wave communication
system. A user equipment (UE) may receive a narrowband signal
component of a synchronization signal for the millimeter wave
communications. The narrowband signal component may include
correlation information. The UE may use the correlation information
to identify a wideband signal component of the synchronization
signal for the millimeter wave communications. The UE may search
frequencies associated with a first frequency location determined
from the correlation information to identify and detect the
wideband signal component of the synchronization signal.
Inventors: |
El Ayach; Omar (San Diego,
CA), Subramanian; Sundar (Bridgewater, NJ), Sampath;
Ashwin (Skillman, NJ), Li; Junyi (Chester, NJ) |
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM Incorporated |
San Diego |
CA |
US |
|
|
Assignee: |
QUALCOMM Incorporated (San
Diego, CA)
|
Family
ID: |
55526773 |
Appl.
No.: |
14/624,723 |
Filed: |
February 18, 2015 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20160087744 A1 |
Mar 24, 2016 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62053012 |
Sep 19, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04J
11/0079 (20130101); H04L 27/2655 (20130101); H04J
11/0086 (20130101); H04L 27/2692 (20130101); H04L
27/2666 (20130101); H04J 11/0069 (20130101); H04W
56/001 (20130101); H04J 2011/0096 (20130101); H04L
1/1812 (20130101) |
Current International
Class: |
H04L
1/18 (20060101); H04W 56/00 (20090101); H04J
11/00 (20060101); H04L 27/26 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2916600 |
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Sep 2015 |
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EP |
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WO-2013071506 |
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May 2013 |
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WO |
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WO-2014069967 |
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May 2014 |
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WO |
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Other References
3GPP, "3rd Generation Partnership Project; Technical Specification
Group Radio Access Network; Evolved Universal Terrestrial Radio
Access (E-UTRA); Physcial channels and modulation (Release 12),"
3GPP TS 36.211 v12.2.0 (Jun. 2014) Technical Specification, Jun.
2014, pp. 1-121, XP_50774046A, 3rd Generation Partnership Project.
cited by applicant .
ISA/EPO, Partial International Search Report of the International
Searching Authority, Int'l App. No. PCT/US2015/046559, Nov. 9,
2015, European Patent Office, Rijswijk, NL, 7 pgs. cited by
applicant .
ISA/EPO, International Search Report and Written Opinion of the
International Searching Authority, Int'l. App. No.
PCT/US2015/046559, Feb. 3, 2016, European Patent Office, Rijswijk,
NL, 17 pgs. cited by applicant .
Tomatis et al., "7: Synchronization and Cell Search," LTE--the UMTS
Long Term Evolution: From Theory to Practice (ed. Sesia et al.),
2009, pp. 141-157, ISBN 978-0-470-69716-0, XP_55064038A, John Wiley
& Sons, Ltd. cited by applicant .
Rhode, Rohde & Schwarz et al.,"TDMA Methods, p. 1 Access
Methods in GSM," XP055302956, 26 pgs., Retrieved from the Internet:
URL:http://firead.pudn.com/downloads161/ebook/733562/GSM/GSM_chap5.pdf.
cited by applicant .
ISA/EPO, Partial International Search Report of the International
Searching Authority, Int'l. App. No. PCT/US2015/046559, Sep. 22,
2016, European Patent Office, Munich, DE, 5 pgs. cited by applicant
.
Taiwan Search Report--TW104127355--TIPO--dated Dec. 6, 2018. cited
by applicant.
|
Primary Examiner: Divito; Walter J
Attorney, Agent or Firm: Holland & Hart LLP
Parent Case Text
CROSS REFERENCES
The present Application for Patent claims priority to U.S.
Provisional Patent Application No. 62/053,012 by El Ayach et al.,
entitled "Directional Synchronization Signals in Wireless
Communications," filed Sep. 19, 2014, and assigned to the assignee
hereof.
Claims
What is claimed is:
1. method for wireless communications, comprising: receiving a
narrowband signal component of a synchronization signal for
millimeter wave communications, the narrowband signal component
comprising correlation information that indicates location
information associated with a wideband signal component of the
synchronization signal; identifying a frequency and timing
associated with the wideband signal component of the
synchronization signal for the millimeter wave communications based
at least in part on the correlation information received in the
narrowband signal component; receiving the wideband signal
component based at least in part on the identified frequency and
timing; and synchronizing with a cell based at least in part on the
narrowband signal component and the wideband signal component.
2. The method of claim 1, wherein the correlation information
comprises encoded information relating to the wideband signal
component of the synchronization signal for the millimeter wave
communications.
3. The method of claim 1, wherein the narrowband signal component
of the synchronization signal and the wideband signal component of
the synchronization signal are received at a similar time.
4. The method of claim 1, further comprising: identifying a source
of the synchronization signal based at least in part on one or more
of a frequency of the narrowband signal component and information
associated with the source encoded in the narrowband signal
component.
5. The method of claim 4, further comprising: identifying, based at
least in part on the identified source, one or more waveform
parameters associated with the wideband signal component of the
synchronization signal.
6. The method of claim 5, wherein the one or more waveform
parameters comprise information associated with at least one of a
pseudorandom noise sequence, a maximum length sequence, and at
least one root of a Zadoff-Chu sequence.
7. The method of claim 6, wherein the at least one root of the
Zadoff-Chu sequence is associated with a frame boundary.
8. The method of claim 5, wherein receiving the wideband signal
component comprises: searching a frequency associated with the one
or more identified one or more waveform parameters.
9. The method of claim 5, further comprising: identifying a timing
reference based at least in part on the identified one or more
waveform parameters associated with the wideband signal
component.
10. The method of claim 1, further comprising: identifying a
hopping pattern associated with the narrowband signal component of
the synchronization signal.
11. The method of claim 10, wherein a periodicity of the hopping
pattern is associated with a frame and the hopping pattern is reset
at a boundary of the frame.
12. The method of claim 10, further comprising: identifying a
timing reference based at least in part on the hopping pattern.
13. The method of claim 1, wherein a first timing reference
conveyed in the narrowband signal component is associated with a
system timing and a second timing reference conveyed in the
wideband signal component is associated with a frame timing.
14. The method of claim 13, wherein the narrowband signal component
comprises a beacon signal and the wideband signal component
comprises a wideband signal.
15. The method of claim 14, wherein the wideband signal comprises
information associated with at least one of a pseudorandom noise
sequence, a maximum length sequence, and at least one root of a
Zadoff-Chu sequence.
16. The method of claim 1, wherein the narrowband signal component
and the wideband signal component of the synchronization signal are
directionally transmitted via one or more beamformed signals.
17. An apparatus for wireless communications, comprising: a
processor; memory in electronic communication with the processor;
and instructions being stored in the memory, the instructions being
executable by the processor to: receive a narrowband signal
component of a synchronization signal for millimeter wave
communications, the narrowband signal component comprising
correlation information that indicates location information
associated with a wideband signal component of the synchronization
signal; identify a frequency and timing associated with the
wideband signal component of the synchronization signal for the
millimeter wave communications based at least in part on the
correlation information received in the narrowband signal
component; receive the wideband signal component based at least in
part on the identified frequency and timing; and synchronize with a
cell based at least in part on the narrowband signal component and
the wideband signal component.
18. The apparatus of claim 17, further comprising instructions
executable by the processor to: identify a source of the
synchronization signal based at least in part on one or more of a
frequency of the narrowband signal component and information
associated with the source encoded in the narrowband signal
component.
19. The apparatus of claim 18, further comprising instructions
executable by the processor to: identify, based at least in part on
the identified source, one or more waveform parameters associated
with the wideband signal component of the synchronization
signal.
20. The apparatus of claim 19, wherein the one or more waveform
parameters comprise information associated with at least one of a
pseudorandom noise sequence, a maximum length sequence, and at
least one root of a Zadoff-Chu sequence.
21. The apparatus of claim 20, wherein the at least one root of the
Zadoff-Chu sequence is associated with a frame boundary.
22. The apparatus of claim 19, wherein receiving the wideband
signal component comprises instructions executable by the processor
to: search a frequency associated with the one or more identified
one or more waveform parameters.
23. The apparatus of claim 19, further comprising instructions
executable by the processor to: identify a timing reference based
at least in part on the identified one or more waveform parameters
associated with the wideband signal component.
24. The apparatus of claim 17, further comprising instructions
executable by the processor to: identify a hopping pattern
associated with the narrowband signal component of the
synchronization signal.
25. The apparatus of claim 24, wherein a periodicity of the hopping
pattern is associated with a frame and the hopping pattern is reset
at a boundary of the frame.
26. An apparatus for wireless communications, comprising: means for
receiving a narrowband signal component of a synchronization signal
for millimeter wave communications, the narrowband signal component
comprising correlation information that indicates location
information associated with a wideband signal component of the
synchronization signal; means for identifying a frequency and
timing associated with the wideband signal component of the
synchronization signal for the millimeter wave communications based
at least in part on the correlation information received in the
narrowband signal component; means for receiving the wideband
signal component based at least in part on the identified frequency
and timing; and means for synchronizing with a cell based at least
in part on the narrowband signal component and the wideband signal
component.
27. The apparatus of claim 26, further comprising: means for
identifying a source of the synchronization signal based at least
in part on one or more of a frequency of the narrowband signal
component and information associated with the source encoded in the
narrowband signal component.
28. The apparatus of claim 27, further comprising: means for
identifying, based at least in part on the identified source, one
or more waveform parameters associated with the wideband signal
component of the synchronization signal.
29. The apparatus of claim 28, wherein the means for receiving the
wideband signal component comprises: means for searching a
frequency associated with the one or more identified one or more
waveform parameters.
30. A non-transitory computer-readable medium storing computer
executable code for wireless communication, the code executable by
a processor to: receive a narrowband signal component of a
synchronization signal for millimeter wave communications, the
narrowband signal component comprising correlation information that
indicates location information associated with a wideband signal
component of the synchronization signal; identify a frequency and
timing associated with the wideband signal component of the
synchronization signal for the millimeter wave communications based
at least in part on the correlation information received in the
narrowband signal component; receive the wideband signal component
based at least in part on the identified frequency and timing; and
synchronize with a cell based at least in part on the narrowband
signal component and the wideband signal component.
Description
BACKGROUND
Field of the Disclosure
The present disclosure relates to wireless communication systems,
and more particularly to directional synchronization signals in
wireless communications.
Description of Related Art
Wireless communication systems are widely deployed to provide
various types of communication content such as voice, video, packet
data, messaging, broadcast, and so on. These systems may be
multiple-access systems capable of supporting communication with
multiple users by sharing the available system resources (e.g.,
time, frequency, and power). Examples of such multiple-access
systems include code-division multiple access (CDMA) systems,
time-division multiple access (TDMA) systems, frequency-division
multiple access (FDMA) systems, and orthogonal frequency-division
multiple access (OFDMA) systems.
By way of example, a wireless multiple-access communication system
may include a number of base stations, each simultaneously
supporting communication for multiple communication devices,
otherwise known as user equipments (UEs). A base station may
communicate with UEs on downlink channels (e.g., for transmissions
from a base station to a UE) and uplink channels (e.g., for
transmissions from a UE to a base station). UEs may locate a base
station by detecting synchronization signal(s), from which the UEs
acquire the base station identification code (cell ID), system
timing information, frame alignment information, etc. In systems
where the receiver is highly signal strength and noise limited
(e.g., millimeter wave systems), beamformed synchronization signals
may be swept across the cell coverage area to provide coverage
enhancement to improve detection.
Conventional cellular synchronization and discovery techniques
generally employ primary and secondary synchronization signals
broadcast at a fixed frame location within the coverage area of a
base station or cell. The UE scans for the primary synchronization
signal (PSS) and, if detected, finds the secondary synchronization
signal (SSS) in the same subframe as the primary synchronization
signal. The PSS/SSS generally include physical layer and cell layer
identity information, respectively, used by the UE to determine the
base station identity. From the identity, the UE is able to
determine the location of reference signals where the UE is able to
perform channel estimation, etc. In these signaling techniques,
however, the location of the SSS is fixed in the same subframe as
the PSS and, therefore, the UE must detect both signals to
determine the base station identity for further
synchronization.
SUMMARY
The described features generally relate to one or more improved
systems, methods, and/or apparatuses for directional
synchronization signals in wireless communications. Certain aspects
of the present description employ a dual-signal synchronization
scheme that includes a narrowband signal and a wideband signal for
millimeter wave communications. The narrowband signal (e.g., a
beacon) may convey portions of the cell ID and at least some timing
information. The wideband signal may convey any remaining portion
of the cell ID and additional timing information. A UE detects the
higher power narrowband signal and then searches for the
accompanying wideband signal. In some examples, the UE may
determine enough cell ID information (e.g., first three bits of the
cell ID) from the narrowband signal to determine the location
(e.g., time/frequency) of the accompanying wideband signal.
Therefore, in some examples, the narrowband signal of a
synchronization signal may be received. The synchronization signal
may be for a millimeter wave communication system. The narrowband
signal may include or otherwise convey location information
associated with the wideband signal of the synchronization signal.
The location information may be a frequency location, a time
location, or combinations thereof. In some examples, the narrowband
signal portion or component of the synchronization signal may also
include timing information associated with the wireless
communication system and/or all or some identification information
associated with the source of the synchronization signal. The
location information may be used to identify the wideband signal of
the synchronization signal. For example, the location information
may be used to determine the frequency and/or the time the wideband
signal will be transmitted and, therefore, used to receive the
wideband signal. Other waveform parameters associated with the
wideband signal may also be included or conveyed in the narrowband
signal. The wideband signal may include or otherwise convey, in
some examples, components of the cell ID and/or timing information
associated with the millimeter wave communication system. In some
examples, a selection of other parameters associated with the
wideband signal may be used to implicitly convey the additional
timing information.
A method of wireless communication at a wireless device is
described. The method may include receiving a narrowband signal
component of a synchronization signal for millimeter wave
communications, the narrowband signal component comprising
correlation information, and using the correlation information to
identify a wideband signal component of the synchronization signal
for the millimeter wave communications.
An apparatus for wireless communication at a wireless device is
described. The apparatus may include means for receiving a
narrowband signal component of a synchronization signal for
millimeter wave communications, the narrowband signal component
comprising correlation information, and means for using the
correlation information to identify a wideband signal component of
the synchronization signal for the millimeter wave
communications.
A further apparatus for wireless communication at a wireless device
is described. The apparatus may include a processor, memory in
electronic communication with the processor, and instructions
stored in the memory, wherein the instructions are executable by
the processor to receive a narrowband signal component of a
synchronization signal for millimeter wave communications, the
narrowband signal component comprising correlation information, and
use the correlation information to identify a wideband signal
component of the synchronization signal for the millimeter wave
communications.
A non-transitory computer-readable medium storing computer
executable code for wireless communication at a wireless device is
described. The code may be executable by a processor to receive a
narrowband signal component of a synchronization signal for
millimeter wave communications, the narrowband signal component
comprising correlation information, and use the correlation
information to identify a wideband signal component of the
synchronization signal for the millimeter wave communications.
In some examples of the method, apparatuses, or non-transitory
computer-readable medium described above, the correlation
information may include at least one of frequency location
information, time location information, and encoded information
relating to the wideband signal component of the synchronization
signal for the millimeter wave communications. Additionally or
alternatively, in some examples the narrowband signal component of
the synchronization signal and the wideband signal component of the
synchronization signal may be received at a similar time.
Some examples of the method, apparatuses, or non-transitory
computer-readable medium described above may further include
identifying a source of the synchronization signal based at least
in part on one or more of a frequency of the narrowband signal
component and information associated with the source encoded in the
narrowband signal component. Additionally or alternatively, some
examples may include identifying, based at least in part on the
identified source, one or more waveform parameters associated with
the wideband signal component of the synchronization signal.
In some examples of the method, apparatuses, or non-transitory
computer-readable medium described above, the one or more waveform
parameters may include information associated with at least one of
a pseudorandom noise sequence, a maximum length sequence, and at
least one root of a Zadoff-Chu sequence. Additionally or
alternatively, in some examples the at least one root of the
Zadoff-Chu sequence is associated with a frame boundary.
In some examples of the method, apparatuses, or non-transitory
computer-readable medium described above, receiving the wideband
signal component includes searching a frequency associated with the
one or more identified one or more waveform parameters.
Additionally or alternatively, some examples may include
identifying a timing reference based at least in part on the
identified one or more waveform parameters associated with the
wideband signal component.
Some examples of the method, apparatuses, or non-transitory
computer-readable medium described above may further include
identifying a hopping pattern associated with the narrowband signal
component of the synchronization signal. Additionally or
alternatively, in some examples a periodicity of the hopping
pattern is associated with a frame and the hopping pattern is reset
at a boundary of the frame.
Some examples of the method, apparatuses, or non-transitory
computer-readable medium described above may further include
identifying a timing reference based at least in part on the
hopping pattern. Additionally or alternatively, in some examples a
first timing reference conveyed in the narrowband signal component
is associated with a system timing and a second timing reference
conveyed in the wideband signal component is associated with a
frame timing.
In some examples of the method, apparatuses, or non-transitory
computer-readable medium described above, the narrowband signal
component includes a beacon signal and the wideband signal
component comprises a wideband signal. Additionally or
alternatively, in some examples the wideband signal includes
information associated with at least one of a pseudorandom noise
sequence, a maximum length sequence, and at least one root of a
Zadoff-Chu sequence.
In some examples of the method, apparatuses, or non-transitory
computer-readable medium described above, the narrowband signal
component and the wideband signal component of the synchronization
signal are directionally transmitted via one or more beamformed
signals.
The foregoing has outlined rather broadly the features and
technical advantages of examples according to the disclosure in
order that the detailed description that follows may be better
understood. Additional features and advantages will be described
hereinafter. The conception and specific examples disclosed may be
readily utilized as a basis for modifying or designing other
structures for carrying out the same purposes of the present
disclosure. Such equivalent constructions do not depart from the
scope of the appended claims. Characteristics of the concepts
disclosed herein, both their organization and method of operation,
together with associated advantages will be better understood from
the following description when considered in connection with the
accompanying figures. Each of the figures is provided for the
purpose of illustration and description only, and not as a
definition of the limits of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
A further understanding of the nature and advantages of the present
invention may be realized by reference to the following drawings.
In the appended figures, similar components or features may have
the same reference label. Further, various components of the same
type may be distinguished by following the reference label by a
dash and a second label that distinguishes among the similar
components. If only the first reference label is used in the
specification, the description is applicable to any one of the
similar components having the same first reference label
irrespective of the second reference label.
FIG. 1 shows a block diagram of a wireless communication system, in
accordance with various aspects of the present disclosure;
FIG. 2 shows a block diagram of a device configured for use in
wireless communication, in accordance with various aspects of the
present disclosure;
FIG. 3 shows a block diagram of a device configured for use in
wireless communication, in accordance with various aspects of the
present disclosure;
FIG. 4 shows a block diagram of a device configured for use in
wireless communication, in accordance with various aspects of the
present disclosure;
FIG. 5 shows a block diagram of a wireless communication system, in
accordance with various aspects of the present disclosure;
FIG. 6 shows a swim diagram illustrating aspects of directional
synchronization signals in wireless communication, in accordance
with various aspects of the present disclosure;
FIG. 7 shows a diagram of an example dual-component synchronization
signal, in accordance with various aspects of the present
disclosure;
FIG. 8 is a flow chart illustrating an example of a method for
wireless communication, in accordance with various aspects of the
present disclosure;
FIG. 9 is a flow chart illustrating an example of a method for
wireless communication, in accordance with various aspects of the
present disclosure; and
FIG. 10 is a flow chart illustrating an example of a method for
wireless communication, in accordance with various aspects of the
present disclosure.
DETAILED DESCRIPTION
According to aspects of the present description, in high frequency
systems (e.g., millimeter wave communication systems), a base
station may employ a dual-component synchronization signal scheme
where two signals are transmitted. A UE may receive the first
signal component of a synchronization signal and then begin to
search for the second component of the synchronization signal. The
combination of the first and second components of the
synchronization signal may generally convey timing information,
cell ID, and/or various other parameters associated with the
wireless communication system. In some examples, the UE may receive
the narrowband signal component and determine various waveform
parameters associated with the wideband signal, e.g., location,
etc. The UE may search the determined location (e.g., frequencies
and/or time) to find the second wideband component of the
synchronization signal. A base station that transmits the
synchronization signal may pair the wideband signal component with
the narrowband signal component based on the identity of the base
station, for example. Accordingly, the UE may determine some or all
of the cell ID information from the narrowband signal and, based on
the cell ID, know where to locate the associated wideband signal
component.
According to additional aspects of the present description, the
location of a narrowband signal may be used to signal or otherwise
convey location information for the wideband signal of the
synchronization signal. Similarly, the narrowband signal may
include other information, such as information regarding the
properties of the wideband signal. A UE may receive the narrowband
signal portion of the synchronization signal of a millimeter wave
communication system and, based on information included or conveyed
in the narrowband signal, identify the wideband signal portion. The
information may include location information such as a frequency
location of the wideband signal, a time location of the wideband
signal, additional parameters of the wideband signal, or
combinations thereof. Accordingly, the UE may be able to monitor
for and receive the wideband signal portion of the synchronization
signal without searching every location. In some examples, the
narrowband signal may include or convey identification information
associated with the source (e.g., base station) transmitting the
synchronization signal. The UE may use the source ID information
(e.g., as a function, via a look-up table, etc.) to determine the
location of the wideband signal.
According to additional aspects of the present disclosure, the
wideband signal may be used to signal or convey additional
parameters. For example, certain timing information may be embedded
in the wideband signal based on a hopping pattern of the narrowband
signal, based on one or more parameters conveyed by the wideband
signal, or combinations thereof. In some examples, the wideband
signal may include various waveform parameters. In some examples,
the waveform parameters may indicate a root of a Zadoff-Chu (ZC)
sequence, or ZC root groups associated with the wideband signal. In
other examples where non-ZC sequences may be used (e.g., a
pseudorandom noise (PN) sequence, a maximum length sequence
(m-sequence), etc.) the waveform parameters may include other
parametrized quantities associated with the sequences, e.g., a
scrambling code parametrized by a random seed.
The following description provides examples, and is not limiting of
the scope, applicability, or examples set forth in the claims.
Changes may be made in the function and arrangement of elements
discussed without departing from the scope of the disclosure.
Various examples may omit, substitute, or add various procedures or
components as appropriate. For instance, the methods described may
be performed in an order different from that described, and various
steps may be added, omitted, or combined. Also, features described
with respect to some examples may be combined in other
examples.
FIG. 1 illustrates an example of a wireless communications system
100 in accordance with various aspects of the disclosure. The
wireless communications system 100 includes base stations 105, UEs
115, and a core network 130. The core network 130 may provide user
authentication, access authorization, tracking, Internet Protocol
(IP) connectivity, and other access, routing, or mobility
functions. The base stations 105 interface with the core network
130 through a first set of backhaul links 132 (e.g., S1, etc.) and
may perform radio configuration and scheduling for communication
with the UEs 115, or may operate under the control of a base
station controller (not shown). In various examples, the base
stations 105 may communicate, either directly or indirectly (e.g.,
through core network 130), with each other over a second set of
backhaul links 134 (e.g., X1, etc.), which may be wired or wireless
communication links.
The base stations 105 may wirelessly communicate with the UEs 115
via one or more base station antennas. Each of the base station 105
sites may provide communication coverage for a respective
geographic coverage area 110. In some examples, base stations 105
may be referred to as a base transceiver station, a radio base
station, an access point, a radio transceiver, a NodeB, eNodeB
(eNB), Home NodeB, a Home eNodeB, or some other suitable
terminology. The geographic coverage area 110 for a base station
105 may be divided into sectors making up only a portion of the
coverage area (not shown). The wireless communications system 100
may include base stations 105 of different types (e.g., macro
and/or small cell base stations). There may be overlapping
geographic coverage areas 110 for different technologies.
In some examples, the wireless communications system 100 is an
LTE/LTE-A network. In LTE/LTE-A networks, the term evolved Node B
(eNB) may be generally used to describe the base stations 105,
while the term UE may be generally used to describe the UEs 115.
The wireless communications system 100 may be a Heterogeneous
LTE/LTE-A network in which different types of eNBs provide coverage
for various geographical regions. For example, each eNB or base
station 105 may provide communication coverage for a macro cell, a
small cell, and/or other types of cell. The term "cell" is a 3GPP
term that can be used to describe a base station, a carrier or
component carrier associated with a base station, or a coverage
area (e.g., sector, etc.) of a carrier or base station, depending
on context. In some examples, the wireless communications system
100 may be, or include a millimeter wave communication network.
A macro cell generally covers a relatively large geographic area
(e.g., several kilometers in radius) and may allow unrestricted
access by UEs with service subscriptions with the network provider.
A small cell is a lower-powered base station, as compared with a
macro cell, that may operate in the same or different (e.g.,
licensed, unlicensed, etc.) frequency bands as macro cells. Small
cells may include pico cells, femto cells, and micro cells
according to various examples. A pico cell may cover a relatively
smaller geographic area and may allow unrestricted access by UEs
with service subscriptions with the network provider. A femto cell
also may cover a relatively small geographic area (e.g., a home)
and may provide restricted access by UEs having an association with
the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs
for users in the home, and the like). An eNB for a macro cell may
be referred to as a macro eNB. An eNB for a small cell may be
referred to as a small cell eNB, a pico eNB, a femto eNB or a home
eNB. An eNB may support one or multiple (e.g., two, three, four,
and the like) cells (e.g., component carriers).
The wireless communications system 100 may support synchronous or
asynchronous operation. For synchronous operation, the base
stations may have similar frame timing, and transmissions from
different base stations may be approximately aligned in time. For
asynchronous operation, the base stations may have different frame
timing, and transmissions from different base stations may not be
aligned in time. The techniques described herein may be used for
either synchronous or asynchronous operations.
The communication networks that may accommodate some of the various
disclosed examples may be packet-based networks that operate
according to a layered protocol stack. In the user plane,
communications at the bearer or Packet Data Convergence Protocol
(PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may
perform packet segmentation and reassembly to communicate over
logical channels. A Medium Access Control (MAC) layer may perform
priority handling and multiplexing of logical channels into
transport channels. The MAC layer may also use Hybrid ARQ (HARD) to
provide retransmission at the MAC layer to improve link efficiency.
In the control plane, the Radio Resource Control (RRC) protocol
layer may provide establishment, configuration, and maintenance of
an RRC connection between a UE 115 and the base stations 105 or
core network 130 supporting radio bearers for the user plane data.
At the Physical (PHY) layer, the transport channels may be mapped
to Physical channels.
The UEs 115 are dispersed throughout the wireless communications
system 100, and each UE 115 may be stationary or mobile. A UE 115
may also include or be referred to by those skilled in the art as a
mobile station, a subscriber station, a mobile unit, a subscriber
unit, a wireless unit, a remote unit, a mobile device, a wireless
device, a wireless communications device, a remote device, a mobile
subscriber station, an access terminal, a mobile terminal, a
wireless terminal, a remote terminal, a handset, a user agent, a
mobile client, a client, or some other suitable terminology. A UE
115 may be a cellular phone, a personal digital assistant (PDA), a
wireless modem, a wireless communication device, a handheld device,
a tablet computer, a laptop computer, a cordless phone, a wireless
local loop (WLL) station, or the like. A UE 115 may be able to
communicate with various types of base stations and network
equipment including macro eNBs, small cell eNBs, relay base
stations, and the like. A UE 115 may also be able to communicate
with other UEs either within or outside the same coverage area of a
base station via D2D communications.
The communication links 125 shown in wireless communications system
100 may include uplink (UL) transmissions from a UE 115 to a base
station 105, and/or downlink (DL) transmissions, from a base
station 105 to a UE 115. The downlink transmissions may also be
called forward link transmissions while the uplink transmissions
may also be called reverse link transmissions. Each communication
link 125 may include one or more carriers, where each carrier may
be a signal made up of multiple sub-carriers (e.g., waveform
signals of different frequencies) modulated according to the
various radio technologies described above. Each modulated signal
may be sent on a different sub-carrier and may carry control
information (e.g., reference signals, control channels, etc.),
overhead information, user data, etc. The communication links 125
may transmit bidirectional communications using FDD (e.g., using
paired spectrum resources) or TDD operation (e.g., using unpaired
spectrum resources). Frame structures for FDD (e.g., frame
structure type 1) and TDD (e.g., frame structure type 2) may be
defined.
In some embodiments of the system 100, base stations 105 and/or UEs
115 may include multiple antennas for employing antenna diversity
schemes to improve communication quality and reliability between
base stations 105 and UEs 115. Additionally or alternatively, base
stations 105 and/or UEs 115 may employ multiple-input,
multiple-output (MIMO) techniques that may take advantage of
multi-path environments to transmit multiple spatial layers
carrying the same or different coded data.
Wireless communications system 100 may support directional
synchronization signal for millimeter wave detection and
synchronization. For example, a millimeter wave base station 105
may transmit a directional synchronization signal in a sweeping
pattern to UEs 115 within its coverage area 110. The base station
105 may configure a narrowband signal of the synchronization signal
to convey correlation information, such as location information
(e.g., based on cell ID information included or conveyed in the
narrowband signal), for a wideband signal of the synchronization
signal. Hereinafter, information regarding the properties of the
wideband signal may be referred to as correlation information. The
base station 105 may link the wideband signal to the location of
the narrowband signal. In some examples, the identification
information of the base station 105 may be included or conveyed in
the narrowband signal. The identification information may convey
the location information, e.g., the UE 115 may perform a function
based on the base station 105 identification number and/or access a
lookup table. The base station 105 may send the wideband signal
component of the synchronization signal according to the
correlation information in the narrowband signal.
A UE 115 may receive the narrowband signal of the synchronization
signal for the millimeter wave communication network and determine
the correlation information associated with the wideband signal
from the narrowband signal. For example, the UE 115 may identify
the base station 105 sending the narrowband signal, may determine
the base station 105 identity based on the frequency of the
narrowband signal, etc., to determine the correlation information.
The UE 115 may use the correlation information to identify and
receive the wideband signal. In some examples, the UE 115 may
determine timing information based on the narrowband signal and/or
the wideband signal components of the synchronization signal, e.g.,
system timing, frame boundary/length timing, etc.
FIG. 2 shows a block diagram 200 of a device 115-a for use in
wireless communication, in accordance with various aspects of the
present disclosure. The device 115-a may be an example of one or
more aspects of a UE 115 described with reference to FIG. 1. The
device 115-a may include a receiver module 205, a synchronization
module 210, and/or a transmitter module 215. The device 115-a may
also be or include a processor (not shown). Each of these modules
may be in communication with each other.
The components of the device 115-a may, individually or
collectively, be implemented using one or more application-specific
integrated circuits (ASICs) adapted to perform some or all of the
applicable functions in hardware. Alternatively, the functions may
be performed by one or more other processing units (or cores), on
one or more integrated circuits. In other examples, other types of
integrated circuits may be used (e.g., Structured/Platform ASICs,
Field Programmable Gate Arrays (FPGAs), and other Semi-Custom ICs),
which may be programmed in any manner known in the art. The
functions of each module may also be implemented, in whole or in
part, with instructions embodied in a memory, formatted to be
executed by one or more general or application-specific
processors.
The receiver module 205 may receive information such as packets,
user data, and/or control information associated with various
information channels (e.g., control channels, data channels, etc.).
The receiver module 205 may receive messages from a millimeter wave
base station 105 including information associated with
synchronization signaling. Information may be passed on to the
synchronization module 210, and to other components of the device
115-a.
The synchronization module 210 may manage synchronization functions
for the device 115-a. The synchronization module 210 may receive,
via the receiver module 205, a narrowband signal of a
synchronization signal for a millimeter wave communication system.
The narrowband signal may include or convey correlation information
associated with a wideband signal of the synchronization signal.
The synchronization module 210 may use the correlation information
to identify and receive, via the receiver module 205, the wideband
signal component of the synchronization signal. In some examples,
the synchronization module 210 may, based on the narrowband signal,
identify the source of the narrowband signal. The synchronization
module 210 may, for example, determine the source identity based on
the frequency of the narrowband signal and/or information encoded
in the narrowband signal. In some examples, the synchronization
module 210 may identify and receive the wideband signal component
based on knowing the source identity.
The transmitter module 215 may transmit the one or more signals
received from other components of the device 115-a. The transmitter
module 215 may transmit information such as packets, user data,
and/or control information to a serving cell. The transmitter
module 215 may send messages to a millimeter wave base station 105
in conjunction with various synchronization signaling operations,
e.g., random access procedures. In some examples, the transmitter
module 215 may be collocated with the receiver module 205 in a
transceiver module.
FIG. 3 shows a block diagram 300 of a device 115-b for use in
wireless communication, in accordance with various examples. The
device 115-b may be an example of one or more aspects of a UE 115
described with reference to FIG. 1. It may also be an example of a
device 115-a described with reference to FIG. 2. The device 115-b
may include a receiver module 205-a, a synchronization module
210-a, and/or a transmitter module 215-a, which may be examples of
the corresponding modules of device 115-a. The device 115-b may
also include a processor (not shown). Each of these components may
be in communication with each other. The synchronization module
210-a may include a synchronization signal detection module 305 and
a timing reference module 310. The receiver module 205-a and the
transmitter module 215-a may perform the functions of the receiver
module 205 and the transmitter module 215, of FIG. 2,
respectively.
The components of the device 115-b may, individually or
collectively, be implemented using one or more application-specific
integrated circuits (ASICs) adapted to perform some or all of the
applicable functions in hardware. Alternatively, the functions may
be performed by one or more other processing units (or cores), on
one or more integrated circuits. In other examples, other types of
integrated circuits may be used (e.g., Structured/Platform ASICs,
Field Programmable Gate Arrays (FPGAs), and other Semi-Custom ICs),
which may be programmed in any manner known in the art. The
functions of each module may also be implemented, in whole or in
part, with instructions embodied in a memory, formatted to be
executed by one or more general or application-specific
processors.
The synchronization signal detection module 305 may manage aspects
of synchronization signal detection and management for the device
115-b. The synchronization signal detection module 305 may, in
cooperation with the receiver module 205-a and/or the transmitter
module 215-a, receive a narrowband signal of a synchronization
signal for millimeter wave communications. The synchronization
signal detection module 305 may determine, based on information
included or conveyed in the narrowband signal, correlation
information for the wideband signal of the synchronization signal.
The correlation information may include location information such
as a frequency location of the wideband signal or a time location
of the wideband signal, or encoded information relating to the
wideband signal, or any combination thereof. In some cases, the
encoded information may be used to determine location information
of the wideband signal. The synchronization signal detection module
305 may identify and receive the wideband signal based on the
correlation information. In some examples, the narrowband signal
and/or the wideband signal may include or convey identification
information associated with the sending base station 105 and timing
information associated with the millimeter wave communication
system. In some cases, the narrowband signal and the wideband
signal may be received simultaneously. In some examples, the
narrowband signal and the wideband signal may be received at
different times.
The timing reference module 310 may manage aspects of
synchronization reference timing for the device 115-b. For example,
the timing reference module 310 may, in cooperation with the
synchronization signal detection module 305, determine one or more
timing references for the device 115-b. In some examples, the
wideband signal may include or convey system timing information,
e.g., fine system timing, for the millimeter wave communication
system. The narrowband signal may include or convey frame timing
information, e.g., frame boundaries, frame length, etc., for the
millimeter wave communication system. In some examples, the
narrowband signal and the wideband signal may include or convey the
frame timing information. The timing reference module 310 may
communicate with the synchronization signal detection module 305 to
determine the timing information included or conveyed in the
narrowband and wideband signal components of the synchronization
signal.
In some examples, the timing reference module 310 may determine the
reference timing information based on a location and/or a hopping
pattern for the wideband signal and/or the narrowband signal. For
example, the narrowband signal may be sent according to a
predetermined hopping pattern such that the hopping pattern is
associated with a frame and the hopping pattern is reset at the
frame boundary. The wideband signal may also be sent according to a
predetermined hopping pattern to convey additional information.
FIG. 4 shows a block diagram 400 of a device 115-c for use in
wireless communication, in accordance with various examples. The
device 115-c may be an example of one or more aspects of a UE 115
described with reference to FIG. 1. It may also be an example of a
device 115-a and/or 115-b described with reference to FIGS. 2 and
3. The device 115-c may include a receiver module 205-b, a
synchronization module 210-b, and/or a transmitter module 215-b,
which may be examples of the corresponding modules of devices 115-a
and/or 115-b. The device 115-c may also include a processor (not
shown). Each of these components may be in communication with each
other. The synchronization module 210-b may include a
synchronization signal detection module 305-a, and a timing
reference module 310-a. The receiver module 205-b and the
transmitter module 215-b may perform the functions of the receiver
module 205 and the transmitter module 215, of FIG. 2,
respectively.
The components of the device 115-c may, individually or
collectively, be implemented using one or more application-specific
integrated circuits (ASICs) adapted to perform some or all of the
applicable functions in hardware. Alternatively, the functions may
be performed by one or more other processing units (or cores), on
one or more integrated circuits. In other examples, other types of
integrated circuits may be used (e.g., Structured/Platform ASICs,
Field Programmable Gate Arrays (FPGAs), and other Semi-Custom ICs),
which may be programmed in any manner known in the art. The
functions of each module may also be implemented, in whole or in
part, with instructions embodied in a memory, formatted to be
executed by one or more general or application-specific
processors.
The synchronization signal detection module 305-a may include a
narrowband signal management module 405 and a wideband signal
management module 410 and may manage aspects of synchronization
signal identification and management for the device 115-c. The
narrowband signal management module 405 may, via the receiver
module 205-b, receive a narrowband signal of a synchronization
signal for millimeter wave communications. The narrowband signal
may include or convey correlation information for a wideband signal
of the synchronization signal. The narrowband signal management
module 405 may use the correlation information to determine and
output information indicative of the location information, e.g., a
frequency of the wideband signal and/or a timing of the wideband
signal. In some examples, the narrowband signal may include
identification information associated with the source base station
105 transmitting the narrowband signal. The location of the
narrowband signal, or correlation information of the narrowband
signal, may convey the identification information, for example. In
another example, the correlation information of the narrowband
signal may be encoded with at least a portion of the identification
information. In some cases, the narrowband signal and the wideband
signal may be received simultaneously, or at a similar time. The
wideband signal may be stored, such as in a buffer or memory, while
the narrowband signal is used to determine information, such as
location information, related to the wideband signal.
The wideband signal management module 410 may receive the
identification information and use it to detect and receive the
wideband signal of the synchronization signal. The wideband signal
management module 410 may search frequencies associated with the
location information. In some examples, the wideband signal
management module 410 may determine, based on the wideband signal,
additional parameters. The narrowband signal may be transmitted via
a predetermined hopping pattern where the hopping pattern may
convey additional information, e.g., frame timing. The hopping
pattern may indicate the frame and be reset at the frame boundary,
e.g., to convey the frame timing information. In some examples, the
additional waveform parameters of the wideband signal may include
information relating to a sequence, such as a ZC sequence, PN
sequence, or an m-sequence, or information indicative of root
groups associated with the wideband signal. The root groups may be
ZC root groups, for example. The wideband signal management module
410 may determine and output information indicative of the root
group information. The additional waveform parameters of the
wideband signal may include information etc.
In some examples, the wideband signal may also include or convey
additional identification information associated with the source
base station. As one example, the narrowband signal may include a
first portion (e.g., first two or three bits of the identification
information) and the wideband signal may include the remaining
portions of the identification information (e.g., the remaining
bits). The wideband signal management module 410, in cooperation
with the narrowband signal management module 405, determine and
output information indicative of the base station identification
information.
The timing reference module 310-a may include a system timing
module 415 and a frame timing module 420 and may manage aspects of
timing operations for the device 115-c. The device 115-c may
generally use system timing information as well as frame timing
information to communicate via the millimeter wave communication
system. The system timing may generally refer to the general
reference timing used by the base station(s) 105 of the millimeter
wave communication system and its communicating UEs 115. The frame
timing may generally refer to the timing of frames, blocks, or
other logical units for control and/or data communications.
The system timing module 415 may, in cooperation with the wideband
signal management module 410, determine the system timing
information based on the wideband signal, for example. For example,
the system timing module 415 may receive the wideband signal and
determine the system timing information or receive information from
the wideband signal management module 410 indicative of the
wideband signal. In some examples, the narrowband signal may
include or convey aspects of the system timing information.
Accordingly, the system timing module 415 may cooperate with the
narrowband signal management module 405 to determine the system
timing information conveyed in the narrowband signal. The system
timing module 415 may output information indicative of the system
timing to other components of the device 115-c for synchronization
operations.
The frame timing module 420 may, in cooperation with the narrowband
signal management module 405, determine the frame timing
information based on the narrowband signal. For example, the frame
timing module 420 may receive the narrowband signal and determine
the frame timing information or receive information from the
narrowband signal management module 405 indicative of the
narrowband signal. In some examples, the wideband signal may also
include or convey frame timing information. The frame timing module
420 may output information indicative of the frame timing to other
components of the device 115-c for synchronization operations.
FIG. 5 shows a system 500 for use in wireless communication, in
accordance with various examples. System 500 may include a UE
115-d, which may be an example of the UEs 115 of FIG. 1. UE 115-d
may also be an example of one or more aspects of devices 115 of
FIGS. 2, 3, and/or 4.
The UE 115-d may generally include components for bi-directional
voice and data communications including components for transmitting
communications and components for receiving communications. The UE
115-d may include antenna(s) 540, a transceiver module 535, a
processor module 505, and memory 515 (including software (SW) 520),
which each may communicate, directly or indirectly, with each other
(e.g., via one or more buses 545). The transceiver module 535 may
communicate bi-directionally, via the antenna(s) 540 and/or one or
more wired or wireless links, with one or more networks, as
described above. For example, the transceiver module 535 may
communicate bi-directionally with base stations 105, with other UEs
115, and/or with devices 115 with reference to FIG. 1, 2, 3, or 4.
The transceiver module 535 may include a modem to modulate the
packets and provide the modulated packets to the antenna(s) 540 for
transmission, and to demodulate packets received from the
antenna(s) 540. While the UE 115-d may include a single antenna
540, the UE 115-d may have multiple antennas 540 capable of
concurrently transmitting and/or receiving multiple wireless
transmissions via carrier aggregation techniques, for example. The
transceiver module 535 may be capable of concurrently communicating
with one or more base stations 105 via multiple component
carriers.
The UE 115-d may include a synchronization signal reception module
510, which may perform the functions described above for the
synchronization module 210 of devices 115 of FIGS. 2, 3, and/or 4.
The UE 115-d may also include a timing configuration module 550.
The timing configuration module 550 may determine, monitor,
control, and/or otherwise manage aspects of synchronization timing
operations for the UE 115-d. The timing configuration module 550
may, based on timing information included or conveyed in the
narrowband signal and/or the wideband signal, determine system
timing parameters and frame timing parameters for the device 115-d.
The reference timing information may provide for communication
between the device 115-d and a base station 105 of a millimeter
wave communication system. Accordingly, the device 115-d may detect
and receive millimeter wave communications with improved
synchronization operations.
The memory 515 may include random access memory (RAM) and read-only
memory (ROM). The memory 515 may store computer-readable,
computer-executable software/firmware code 520 containing
instructions that, when executed, cause the processor module 505 to
perform various functions described herein (e.g., perform
synchronization operations, synchronize reference timing
parameters, etc.). Alternatively, the computer-readable,
computer-executable software/firmware code 520 may not be directly
executable by the processor module 505 but cause a computer (e.g.,
when compiled and executed) to perform functions described herein.
The processor module 505 may include an intelligent hardware
device, e.g., a central processing unit (CPU), a microcontroller,
an application-specific integrated circuit (ASIC), etc.
FIG. 6 is a swim diagram 600 illustrating aspects of
synchronization operations, in accordance with various aspects of
the present disclosure. The diagram 600 may illustrate aspects of
the system 100 and/or 500 described with reference to FIG. 1 or 5,
respectively. The diagram 600 includes a UE 605 and a source cell
610. The UE 605 may be an example of one or more of the UEs 115
and/or devices 115 described above with respect to FIGS. 1, 2, 3,
4, and/or 5. The source cell 610 may be an example of one or more
of the base stations 105 described above with respect to FIG. 1.
Generally, the diagram 600 illustrates aspects of implementing
directional synchronization signaling in millimeter wave
communication systems. In some examples, a system device, such as
one of the UEs 115 and/or base stations 105 may execute one or more
sets of codes to control the functional elements of the device to
perform some or all of the functions described below.
At block 615, the source cell 610 sends a narrowband signal of a
synchronization signal for millimeter wave wireless communications.
The narrowband signal may include or otherwise convey correlation
information associated with a wideband signal for the
synchronization signal. For example, the narrowband signal may
include or convey frequency location information for the wideband
signal, time location information for the wideband signal, or
combinations thereof. The narrowband signal may, for example,
include or convey identification information associated with the
source cell 610. The narrowband signal may also include or convey
timing reference information. At block 620, the UE 605 may identify
the timing reference information. In some aspects, the UE 605 may
identify system timing information based on the narrowband signal,
frame timing information based on the narrowband signal, or
combinations thereof.
At block 625, the UE 605 may determine the location information for
the wideband signal. In some cases, the correlation information is
used to determine the location information for the wideband signal.
For example, the UE 605 may use the identification information of
the source cell 610 to determine the location information for the
wideband signal. The location information may be a frequency
location for the wideband signal, for example. At 630, the source
cell 610 may send the wideband signal to the UE 605, which knows
which location to monitor to receive the wideband signal based on
the location information. Accordingly, the UE 605 may receive the
wideband signal without having to monitor, receive, and/or process
every location where the wideband signal could be sent. The
wideband signal may include or convey additional timing reference
information, e.g., system timing information, frame timing
information, or combinations thereof. In some examples, a hopping
pattern of the narrowband signal may convey additional timing
information. At block 635, the UE 605 may identify the additional
timing information based on the wideband signal. Accordingly, the
UE 605 may detect and receive the narrowband and wideband signals
of the synchronization signal to synchronize with the source cell
610.
FIG. 7 is a diagram 700 illustrating aspects of an example
synchronization signal, in accordance with various aspects of the
present disclosure. The diagram 700 may illustrate aspects of the
system 100 and/or 500 described with reference to FIG. 1 or 5,
respectively. One or more of the UEs 115 and/or devices 115
described above with respect to FIGS. 1, 2, 3, 4, and/or 5 may
implement aspects of the diagram 700. In some examples, a system
device, such as one of the UEs 115 and/or base stations 105 may
execute one or more sets of codes to control the functional
elements of the device to perform some or all of the functions
illustrated with respect to diagram 700.
The diagram 700 may include a narrowband signal 705 and a wideband
signal 710 of a synchronization signal for millimeter wave
communications. The narrowband signal 705 may have an amplitude
greater than the wideband signal. The narrowband signal 705 may be
transmitted at a location (e.g., a frequency) selected to convey
location information associated with the wideband signal 710. For
example, the location of the narrowband signal 705 may be
associated with an identity of the source cell transmitting the
narrowband signal 705. A UE receiving the narrowband signal 705 may
use the location of the narrowband signal to determine the location
of the wideband signal 710 based on the identification of the
source cell. For example, the source cell may be associated with
wideband signals at predetermined locations (e.g., frequency/time).
In some cases, parameters or information associated with the
narrowband signal 705 may be used to convey the location of the
wideband signal 710. For example, a timing, a frequency, an
amplitude, or other parameters of the narrowband signal 705, or
information encoded in the narrowband signal 705, may be used to
convey the location of the wideband signal 710. The narrowband
signal 705 may also include or convey timing reference information
for the millimeter wave communication system. For example, the
narrowband signal 705 may include or convey system timing
information, frame timing information, or combinations thereof. In
some examples, the narrowband signal 705 may sent according to a
predetermined hopping pattern where the hopping pattern conveys
timing information.
The wideband signal 710 may have a wider bandwidth with respect to
the narrowband signal 705. The wideband signal 710 may span one or
more frequencies and include additional identification information
for the source cell as well as additional timing reference
information. In some examples, the wideband signal 710 may hop
across frequencies such that the hopping pattern conveys the timing
information. The additional timing information may be system timing
information, frame timing information, or combinations thereof. In
some examples, the narrowband signal 705 may convey the frame
timing information and the wideband signal 710 may convey the
system timing information. In some examples, the wideband signal
710 may also include or convey other waveform parameters, such as
information relating to a ZC sequence, a PN sequence, an
m-sequence, etc. For example, the wideband signal 710 may include
or convey information identifying one or more root groups for the
wideband signal 710 (e.g., ZC root groups). As discussed, the
location information for the wideband signal 710 may be included or
conveyed in the narrowband signal 705.
FIG. 8 is a flow chart illustrating an example of a method 800 for
wireless communication, in accordance with various aspects of the
present disclosure. For clarity, the method 800 is described below
with reference to aspects of one or more of the UEs described with
reference to FIG. 1, 6, or 7, and/or aspects of one or more of the
devices described with reference to FIG. 2, 3, 4, or 5. In some
examples, a UE may execute one or more sets of codes to control the
functional elements of the UE to perform the functions described
below. Additionally or alternatively, the UE may perform one or
more of the functions described below using special-purpose
hardware.
At block 805, the method 800 may include the UE receiving a
narrowband signal component of a synchronization signal for
millimeter wave communications. The narrowband signal component may
include correlation information. The correlation information may
indicate a location of a wideband signal. The narrowband signal may
also include or convey timing reference information for the
millimeter wave communications. At block 810, the UE may use the
correlation information to identify the wideband signal component
of the synchronization signal for the millimeter wave
communications. For instance, the UE may search the frequencies
associated with the correlation information to detect and receive
the wideband signal.
The operation(s) at blocks 805 and 810 may be performed using the
synchronization module 210 and/or the synchronization signal
reception module 510 described with reference to FIG. 2, 3, 4, or
5.
Thus, the method 800 may provide for wireless communication. It
should be noted that the method 800 is just one implementation and
that the operations of the method 800 may be rearranged or
otherwise modified such that other implementations are
possible.
FIG. 9 is a flow chart illustrating an example of a method 900 for
wireless communication, in accordance with various aspects of the
present disclosure. For clarity, the method 900 is described below
with reference to aspects of one or more of the UEs described with
reference to FIG. 1, 6, or 7, and/or aspects of one or more of the
devices described with reference to FIG. 2, 3, 4, or 5. In some
examples, a UE may execute one or more sets of codes to control the
functional elements of the UE to perform the functions described
below. Additionally or alternatively, the UE may perform one or
more of the functions described below using special-purpose
hardware.
At block 905, the method 900 may include the UE receiving a
narrowband signal component of a synchronization signal for
millimeter wave communications. The narrowband signal component may
include correlation information. The correlation information may
indicate a location of a wideband signal. The narrowband signal may
also include or convey timing reference information for the
millimeter wave communications. At block 910, the UE may identify a
source of the synchronization signal based at least in part on a
frequency of the narrowband signal component and/or information
associated with the source encoded in the narrowband signal
component. In some examples, the frequency of the narrowband signal
may convey the identification information for the source.
At block 915, the UE may use the correlation information and the
identified source to identify the wideband signal component of the
synchronization signal for the millimeter wave communications. For
instance, the UE may use the frequency and/or identity information
to determine which frequencies to search for the wideband signal
component. Accordingly, at block 920 the UE may use the search the
frequencies associated with the correlation information to detect
and receive the wideband signal component of the synchronization
signal.
The operation(s) at blocks 905, 910, 915, and 920 may be performed
using the synchronization module 210 and/or the synchronization
signal reception module 510 described with reference to FIG. 2, 3,
4, or 5.
Thus, the method 900 may provide for wireless communication. It
should be noted that the method 900 is just one implementation and
that the operations of the method 900 may be rearranged or
otherwise modified such that other implementations are
possible.
FIG. 10 is a flow chart illustrating an example of a method 1000
for wireless communication, in accordance with various aspects of
the present disclosure. For clarity, the method 1000 is described
below with reference to aspects of one or more of the UEs described
with reference to FIG. 1, 6, or 7, and/or aspects of one or more of
the devices described with reference to FIG. 2, 3, 4, or 5. In some
examples, a UE may execute one or more sets of codes to control the
functional elements of the UE to perform the functions described
below. Additionally or alternatively, the UE may perform one or
more of the functions described below using special-purpose
hardware.
At block 1005, the method 1000 may include the UE receiving a
narrowband signal component of a synchronization signal for
millimeter wave communications. The narrowband signal component may
include correlation information. The correlation information may
indicate a location of a wideband signal. The narrowband signal may
also include or convey timing reference information for the
millimeter wave communications. At block 1010, the UE may identify
a source of the synchronization signal based at least in part on a
frequency of the narrowband signal component and/or information
associated with the source encoded in the narrowband signal
component. In some examples, the frequency of the narrowband signal
may convey the identification information for the source.
At block 1015, the UE may use the identified source to identify one
or more waveform parameters associated with the wideband signal
component of the synchronization signal for the millimeter wave
communications. For instance, the UE may use the identity
information to determine which frequencies to search for the
wideband signal component. Accordingly, at block 1020 the UE may
use the search the frequencies associated with the correlation
information to detect and receive the wideband signal component of
the synchronization signal.
The operation(s) at blocks 1005, 1010, 1015, and 1020 may be
performed using the synchronization module 210 and/or the
synchronization signal reception module 510 described with
reference to FIG. 2, 3, 4, or 5.
Thus, the method 1000 may provide for wireless communication. It
should be noted that the method 1000 is just one implementation and
that the operations of the method 1000 may be rearranged or
otherwise modified such that other implementations are
possible.
In some examples, aspects from two or more of the methods 800, 900,
and/or 1000 may be combined. It should be noted that the methods
800, 900, and 1000 are just example implementations, and that the
operations of the methods 800-1000 may be rearranged or otherwise
modified such that other implementations are possible.
Techniques described herein may be used for various wireless
communications systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA,
and other systems. The terms "system" and "network" are often used
interchangeably. A CDMA system may implement a radio technology
such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc.
CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000
Releases 0 and A are commonly referred to as CDMA2000 1.times.,
1.times., etc. IS-856 (TIA-856) is commonly referred to as CDMA2000
1.times.EV-DO, High Rate Packet Data (HRPD), etc. UTRA includes
Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may
implement a radio technology such as Global System for Mobile
Communications (GSM). An OFDMA system may implement a radio
technology such as Ultra Mobile Broadband (UMB), Evolved UTRA
(E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20,
Flash-OFDM.TM., etc. UTRA and E-UTRA are part of Universal Mobile
Telecommunication System (UMTS). 3GPP Long Term Evolution (LTE) and
LTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA.
UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents
from an organization named "3rd Generation Partnership Project"
(3GPP). CDMA2000 and UMB are described in documents from an
organization named "3rd Generation Partnership Project 2" (3GPP2).
The techniques described herein may be used for the systems and
radio technologies mentioned above as well as other systems and
radio technologies, including cellular (e.g., LTE) communications
over an unlicensed and/or shared bandwidth. The description above,
however, describes an LTE/LTE-A system for purposes of example, and
LTE terminology is used in much of the description above, although
the techniques are applicable beyond LTE/LTE-A applications.
The detailed description set forth above in connection with the
appended drawings describes examples and does not represent the
only examples that may be implemented or that are within the scope
of the claims. The terms "example" and "exemplary," when used in
this description, mean "serving as an example, instance, or
illustration," and not "preferred" or "advantageous over other
examples." The detailed description includes specific details for
the purpose of providing an understanding of the described
techniques. These techniques, however, may be practiced without
these specific details. In some instances, well-known structures
and apparatuses are shown in block diagram form in order to avoid
obscuring the concepts of the described examples.
Information and signals may be represented using any of a variety
of different technologies and techniques. For example, data,
instructions, commands, information, signals, bits, symbols, and
chips that may be referenced throughout the above description may
be represented by voltages, currents, electromagnetic waves,
magnetic fields or particles, optical fields or particles, or any
combination thereof.
The various illustrative blocks and components described in
connection with the disclosure herein may be implemented or
performed with a general-purpose processor, a digital signal
processor (DSP), an ASIC, an FPGA or other programmable logic
device, discrete gate or transistor logic, discrete hardware
components, or any combination thereof designed to perform the
functions described herein. A general-purpose processor may be a
microprocessor, but in the alternative, the processor may be any
conventional processor, controller, microcontroller, or state
machine. A processor may also be implemented as a combination of
computing devices, e.g., a combination of a DSP and a
microprocessor, multiple microprocessors, one or more
microprocessors in conjunction with a DSP core, or any other such
configuration.
The functions described herein may be implemented in hardware,
software executed by a processor, firmware, or any combination
thereof. If implemented in software executed by a processor, the
functions may be stored on or transmitted over as one or more
instructions or code on a computer-readable medium. Other examples
and implementations are within the scope and spirit of the
disclosure and appended claims. For example, due to the nature of
software, functions described above can be implemented using
software executed by a processor, hardware, firmware, hardwiring,
or combinations of any of these. Features implementing functions
may also be physically located at various positions, including
being distributed such that portions of functions are implemented
at different physical locations. As used herein, including in the
claims, the term "and/or," when used in a list of two or more
items, means that any one of the listed items can be employed by
itself, or any combination of two or more of the listed items can
be employed. For example, if a composition is described as
containing components A, B, and/or C, the composition can contain A
alone; B alone; C alone; A and B in combination; A and C in
combination; B and C in combination; or A, B, and C in combination.
Also, as used herein, including in the claims, "or" as used in a
list of items (for example, a list of items prefaced by a phrase
such as "at least one of" or "one or more of") indicates a
disjunctive list such that, for example, a list of "at least one of
A, B, or C" means A or B or C or AB or AC or BC or ABC (i.e., A and
B and C).
Computer-readable media includes both computer storage media and
communication media including any medium that facilitates transfer
of a computer program from one place to another. A storage medium
may be any available medium that can be accessed by a general
purpose or special purpose computer. By way of example, and not
limitation, computer-readable media can comprise RAM, ROM, EEPROM,
flash memory, CD-ROM or other optical disk storage, magnetic disk
storage or other magnetic storage devices, or any other medium that
can be used to carry or store desired program code means in the
form of instructions or data structures and that can be accessed by
a general-purpose or special-purpose computer, or a general-purpose
or special-purpose processor. Also, any connection is properly
termed a computer-readable medium. For example, if the software is
transmitted from a website, server, or other remote source using a
coaxial cable, fiber optic cable, twisted pair, digital subscriber
line (DSL), or wireless technologies such as infrared, radio, and
microwave, then the coaxial cable, fiber optic cable, twisted pair,
DSL, or wireless technologies such as infrared, radio, and
microwave are included in the definition of medium. Disk and disc,
as used herein, include compact disc (CD), laser disc, optical
disc, digital versatile disc (DVD), floppy disk and Blu-ray disc
where disks usually reproduce data magnetically, while discs
reproduce data optically with lasers. Combinations of the above are
also included within the scope of computer-readable media.
The previous description of the disclosure is provided to enable a
person skilled in the art to make or use the disclosure. Various
modifications to the disclosure will be readily apparent to those
skilled in the art, and the generic principles defined herein may
be applied to other variations without departing from the scope of
the disclosure. Thus, the disclosure is not to be limited to the
examples and designs described herein but is to be accorded the
broadest scope consistent with the principles and novel features
disclosed herein.
* * * * *
References